Honestly, it would be interesting if there was a little button to click on.
Because, after visiting several websites, I really can't see a little button anywhere in my browser to click. ☹️

I’ve just installed Flagfox https://addons.mozilla.org/nl/firefox/addon/flagfox/
And yes, as already mentioned by user arnofly, this works flawless,
the Flag is visible in the address bar when you open a webpage immediately after installing the extension.

All the information in one place..you can view the hosting provider,IP Address,DNS records and who-is information.excellent plug-in.

Better extension for Firefox 57+ I tried, but not as good as Flagfox

As someone that's always researching web space for my own sites, this is a
very cool little gizmo for quickly determining who hosts my favourite sites. Well done.

It is very handy tool to get the DNS records of domain instantly.

It's exactly what I was looking for so long. It tells you web hosting provider, WHOIS information and DNS lookup of the domain. Its 3 in 1 actually. Excellent plugin, Kudos to developers.

This is a great tool to check DNS records. Exactly what i was looking for.

Quick and easy way to find out which web hosting company is hosting a particular website.

this is the exact tool which can assist me to check the domain/website details while I am on the helpdesk. Good Job..

This is exactly what I was looking for. I can get all details on who is hosting any particular site.

Best plugin to find websites information directly from the browser.